I got new discs and pads around 3 months ago now as when I bought the car the brakes were pretty much finished and there was a shuddering feel under braking. New brakes fitted and were spot on till about 4 weeks after and only around 800 miles when the shuddering started again. No very hard breaking. Bedded in properly. At the same time as the brakes I had new tyres fitted with wheels re balanced plus laser alignment and new lower ball joints. I was sent new discs under warranty and fitted. I was told the pads would be fine as they only had around 800 miles on them so they were cleaned and put back on. This stopped the shuddering like the first time but now it has come back again. Any ideas what could be causing this? Cheers Jack
I've had the car on a rolling road test and the indicators were fluctuating like crazy so it is the discs that are warped
I thought this the first time it happened and made sure everything was spotless before new ones went on. Could a seized calliper cause this recurring problem? Hub bearings?
Could be a seized calliper yes.. If the Pistons weren't disengaging, it would cause heat build up and possible deformation. Brake tester (mot station) would confirm. Sent from my iPhone using Tapatalk
Sounds to me like you've either got a sticky caliper causing a lot of heat, this would be fairly obvious by one side having a lot of run out and not the other, more worn pads on one side etc etc, or you're getting a lot of pad left over on the disc, I'd try going out and hammering the brakes, might clear it, first thing would be remove pads and have a good inspection though
Was wondering what the rolling road tester is that has a device that measures disc throw out, not see one before
You need to be checking disc run out with a dti, also check the hub run out too. Poorly cleaned mating face, pad deposits on discs could all be a cause too. As said you need to make sure you don't have any sticking pads and all your pistons are free. A lot of brake judder I've come across has been caused by pad deposit build up and not warped discs! Sent from my iPhone using Tapatalk
I've been out and gone through another bedding on process to get rid of excess deposits and it's made no difference. 10 runs of firm braking from 60-20
The test was carried out at kwik fit. I have no idea how it work but the machine rolls the wheels, I think the mechanic hold the brakes lightly and it measures fluctuations in the braking. The needles both sides (one for each brake) were all over the show
I'm going to get all Pistons checked and do a run out test done. Will keep the thread updated. Cheers for all the replies chaps. Much appreciated
Try a moe extremely bedding in. 90-50 medium pedal x5 then 100-50 hard x5. This is the procedure I followed for my Pagids rs29s and they've been faultless after 5 trackdays, albeit with an AP 4 pot set up.
Kwik Fit says it all, yes you'll see fluctuations in brake rollers but that doesn't deter what the issue. To do it all properly it needs checking with a DTi, they'll happily tell you that you need discs and pads as it all bonus and target related there. Sent from my iPhone using Tapatalk
I know it would take a huge amount of energy to 'warp discs'. But a seized piston causing the pad to rest on the disc after braking would cause deformation of the disc
New discs and pads going in tomorrow. Turns out to be a bad compound mix on the pads causing very high heat in small areas of the pad thus causing dvt. going to make sure everywhere is spotless before reassembling, hub coming off etc, new fluid and some proper bedding in.
Just a bit of an update.... Had new discs and pads put on today . The old pads (only around 5000 miles) had some spots of silver, almost like sheer metal, on them in a few different places leading us believe they were causing extremely high levels of heat in those particular areas. The new set up feels solid as a rock for now. Will post anymore updates worthwhile knowing.
Pretty well all brake juddder is caused by pad material deposited into the 'pores' of the disc. Normally when soft pads get too hot. These deposits cause high spots on the disc which get worse when hot (as the material expands) It's caused by a combination of pad and disc material and quality, and also when the pads/discs are used outside of their temperature operating window, ie run too hot. If bad, the only resolution is to skim the discs. Sometimes a harder pad can be used 'clean' the surface of the discs, but only if the deposits aren't too bad. Here is a picture of the standard discs after a track days using a development pad, Carbotech XP24 (race endurance pad), which left horrendous deposits, but in this instance due to the standard disc design and material spec. The standard discs design isn't good enough for hard track work. They don't have an internal vane design which means cooling air isn't sucked through the centre of the disc to cool it.
Suffered from the exact same problem on the ring last weekend, brakes started juddering like mad, the more heat that went in the bigger the problem got. After properly cooling down all problems went away. Cl5+ pads will be bought for the next time i go to the ring, i'll use standard pads for the rest of the year as i do 95% of highway driving.
